Hu reviews test characterization methods for passive integrated photonics components, including fiber-to-chip coupling schemes, waveguides, spirals, Mach Zehnder Interferometers, Y-splitters, ring resonators, and directional couplers. This white paper covers the basic principles of optical testing directly on wafers and the best measurement methods for both active and passive components present on the PIC chip. A PIC is a compact photonic system that enables complex functionalities by combining tens, hundreds or even thousands. The Optical Loss Analyzer (OLA) test solution measures Insertion Loss, Polarization Dependent Loss and Return Loss.